As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.
This version is dated 1 November 2019.
(1) What type of RFC is being requested (BCP, Proposed Standard, Internet
Standard, Informational, Experimental, or Historic)? Why is this the proper
type of RFC? Is this type of RFC indicated in the title page header?
Experimental.
We could have justed proposed for PS. If it's an experiment then this
experiment COULD be short-lived and successful if implemented and deployment
experience gained. The reasons why this is an experiment, is that although
the mechanism itself might be simple: there are interactions between
different layers needed to gain the benefit; and implementations would be
needed in the network as well as the host; and finally there could be changes
needed in operational practice. That's something where a little experience
might cause us to be able to specify/guide more. We don't know what that
would be at this moment. It would fail if no-one used it. At least in the
transport area, we have tried to avoid predicting the future - even to
predict the timescale over which an experiment with multiple parts might
conclude. Although, if the WG later decides it fails, then the experiment
will surely become historic. See also section 9 "Experiment Goals"
(2) The IESG approval announcement includes a Document Announcement Write-Up.
Please provide such a Document Announcement Write-Up. Recent examples can be
found in the "Action" announcements for approved documents. The approval
announcement contains the following sections:
Technical Summary:
This document specifies a new IPv6 Hop-by-Hop option that is used to
record the minimum Path MTU along the forward path between a source
host to a destination host. The recorded value can then be
communicated back to the source using the return Path MTU field in
the option.
Working Group Summary:
This document is the product of the 6man working group. It is a part of the
ongoing effort of improving path MTU discovery in the Internet. The mechanism
described has been implemented as part of an IETF hackathon. It has undergone
thorough review by multiple working group participants. It is experimental as
described above.
Was there anything in WG process that is worth noting? For example, was there
controversy about particular points or were there decisions where the consensus
was particularly rough?
Making PMTUD work better is multi faceted and there are uncertainties in the
WG regarding the deployability of this mechanism. That's also why it is
experimental.
Document Quality:
Are there existing implementations of the protocol? Have a significant number
of vendors indicated their plan to implement the specification? Are there any
reviewers that merit special mention as having done a thorough review, e.g.,
one that resulted in important changes or a conclusion that the document had no
substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other
expert review, what was its course (briefly)? In the case of a Media Type
review, on what date was the request posted?
There are multiple prototype implementations of this mechanism as described
in the implementation section of the draft.
Personnel:
Document Shepherd: Ole Troan
Responsible Area Director: Erik Kline
(3) Briefly describe the review of this document that was performed by the
Document Shepherd. If this version of the document is not ready for
publication, please explain why the document is being forwarded to the IESG.
The document shepherd has implemented the mechanism described in this
document. The document shepherd has also reviewed the document in detail,
both for language and technical issues over 3 iterations. This work is part
of chair's experiment to see if a much more thorough review at the working
group level correlates with fewer changes introduced by the IESG.
(4) Does the document Shepherd have any concerns about the depth or breadth of
the reviews that have been performed?
No.
This document has followed the 6MAN WG process with a WGLC to the list (28
responses) the volunteered reviewers (Matt Smith/Michael Dougherty) and three
thorough chair's / document shepherd reviews. In addition Jen Linkova,
Fernando Gont and Mark Smith has performed extensive reviews. See also
section 12 in the document.
(5) Do portions of the document need review from a particular or from broader
perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or
internationalization? If so, describe the review that took place.
This document and mechanism was initiated from a collaboration between the
6man and the transport working group.
(6) Describe any specific concerns or issues that the Document Shepherd has
with this document that the Responsible Area Director and/or the IESG should be
aware of? For example, perhaps he or she is uncomfortable with certain parts of
the document, or has concerns whether there really is a need for it. In any
event, if the WG has discussed those issues and has indicated that it still
wishes to advance the document, detail those concerns here.
This is the first HBH option that can have Internet wide use(fullness). The
WG has discussed at length if it is deployable. There is of course a feedback
loop between a useful option with implementation and deployability /
drop-rate in the Internet. There is significant uncertainty here, which is
why we want to conduct this experiment. Can a notionally useful HBH option
resolve the deadlock of Internet wide handling of HBH options? Secondarily
can this option find a use within a limited domain?
(7) Has each author confirmed that any and all appropriate IPR disclosures
required for full conformance with the provisions of BCP 78 and BCP 79 have
already been filed. If not, explain why?
Yes, confirmed.
(8) Has an IPR disclosure been filed that references this document? If so,
summarize any WG discussion and conclusion regarding the IPR disclosures.
Yes, there is an IPR filed.
Apart from the chair making the working group aware of the IPR, there has
been no discussion of the IPR claims. The WG does not believe it is in it's
area to make conclusions about IPR claims.
(9) How solid is the WG consensus behind this document? Does it represent the
strong concurrence of a few individuals, with others being silent, or does the
WG as a whole understand and agree with it?
The document has solid consensus.
(10) Has anyone threatened an appeal or otherwise indicated extreme discontent?
If so, please summarise the areas of conflict in separate email messages to the
Responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)
No.
(11) Identify any ID nits the Document Shepherd has found in this document.
(See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist).
Boilerplate checks are not enough; this check needs to be thorough.
There are no nits.
The references to old documents are intentional.
(12) Describe how the document meets any required formal review criteria, such
as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A
(13) Have all references within this document been identified as either
normative or informative?
Yes.
(14) Are there normative references to documents that are not ready for
advancement or are otherwise in an unclear state? If such normative references
exist, what is the plan for their completion?
No.
(15) Are there downward normative references references (see RFC 3967)? If so,
list these downward references to support the Area Director in the Last Call
procedure.
No.
(16) Will publication of this document change the status of any existing RFCs?
Are those RFCs listed on the title page header, listed in the abstract, and
discussed in the introduction? If the RFCs are not listed in the Abstract and
Introduction, explain why, and point to the part of the document where the
relationship of this document to the other RFCs is discussed. If this
information is not in the document, explain why the WG considers it unnecessary.
No.
(17) Describe the Document Shepherd's review of the IANA considerations
section, especially with regard to its consistency with the body of the
document. Confirm that all protocol extensions that the document makes are
associated with the appropriate reservations in IANA registries. Confirm that
any referenced IANA registries have been clearly identified. Confirm that newly
created IANA registries include a detailed specification of the initial
contents for the registry, that allocations procedures for future registrations
are defined, and a reasonable name for the new registry has been suggested (see
RFC 8126).
Confirmed.
(The new HBH option described in the document has already a temporary
allocation from IANA.)
(18) List any new IANA registries that require Expert Review for future
allocations. Provide any public guidance that the IESG would find useful in
selecting the IANA Experts for these new registries.
No new IANA registries.
(19) Describe reviews and automated checks performed by the Document Shepherd
to validate sections of the document written in a formal language, such as XML
code, BNF rules, MIB definitions, YANG modules, etc.
N/A
(20) If the document contains a YANG module, has the module been checked with
any of the recommended validation tools
(https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module comply
with the Network Management Datastore Architecture (NMDA) as specified in
RFC8342?
N/A